1. Field of the Invention
The present invention relates to a turbofan and a mold for manufacturing the same, and more particularly, to a turbofan and a mold for manufacturing the same, which enables the turbofan to be integrally molded by a single molding process.
2. Description of the Related Art
Generally, a turbofan is a type of centrifugal fan, which is adapted to blow air generated from rotating blades. As shown in FIG. 1, a turbofan comprises a circular rotating plate 1 having a central hub 1a to which a rotating shaft of a drive motor (not shown) is coupled, a plurality of blades 2 which are radially disposed at a periphery of the circular rotating plate 1 with regular intervals therebetween such that the plurality of blades 2 are positioned to be perpendicular to the circular rotating plate 1, and a ring-shaped shroud 3 coupled to free ends of the plurality of blades 2 to support the plurality of blades 2.
The turbofan is usually produced by a plastic injection molding process. Since a configuration of the turbofan is complicated, the turbofan is provided with a number of undercuts at the plurality of blades 2, thereby causing a separation of a mold therefrom to be difficult. Therefore, the turbofan is hard to integrally mold by only one molding process. To overcome this disadvantage, a conventional turbofan is produced such that a part A, in which the circular rotating plate 1 and the plurality of blades 2 are integrally molded, and the shroud part 4 are first molded by separate molds, as shown in FIG. 2, and the part A and the shroud part 4 are combined with each other by an ultrasonic fusion or a heat fusion in a subsequent procedure.
However, since the conventional turbofans are produced by a process of molding a plurality of components in the separate molds and joining the plurality of components together, productivity of the conventional turbofans is decreased due to the complicated manufacturing process. Furthermore, since the conventional process of manufacturing turbofans requires a plurality of molds for the plurality of components, manufacturing costs are drastically increased due to production of the molds. Further, since the plurality of components is joined to one another afterward, a defective fraction of products is increased by a poor assembly.